Temperature responsive safety valve



Nov. 21, 1950 D. F. DROW 2,530,942

TEMPERATURE RESPONSIVE SAFETY VALVE FOR FUEL BURNER sYs'rEus Filed Oct. 31, 1947 2 Sheets-Sheet 1 I N V EN TOR. 90/74/09. fi/vn/ Nov. 21, 1950 D. F. DROW ,94

TEMPERATURE RESPONSIVE SAFETY VALVE FOR FUEL BURNER SYSTEMS Filed Oct. 31, 1947 Sheets-Sheet 2 Ill IN VEN TOR. 00/14/0 0/0/4 Pmma Nov. '21, 1950 TEMPERATURE RESPONSIVE SAFETY VALVE FOR FUEL BURNER SYSTEMS Donald F. Drow, Los Angeles, Calif., assignor, by mesne assignments, to Minneapolis-Honeywell Regulator Company, a corporation of Delaware Application October 31, 1947, Serial No. 783,284

6 Claims. (Cl. 158117.1)

The invention relates to valve mechanisms adapted to control the flow of gas or other fuel to the main burner of a heating appliance and being responsive to the presence of a flame at the pilot burner so as to automatically shut off the flow of fuel to the main burner on extinguishing of the pilot burner.

An object of the present invention is to provide an automatically controlled valve mechanism of the character described which utilizes in its combination an improved form of temperature responsive device and affords what is commonly known as safe lighting that is the provision of means for preventing the flow of fuel to the main burner during the operation of resetting the mechanism after extinguishing of the pilot flame, and which may additionally aiford what is commonly referred to as 100% control or shut off wherein the fuel flow to the pilot burner as well as to the main burner is shut off upon extinguishing of the pilot burner.

Another object of the invention is to provide a safety valve of the character described incorporating an improved form of resetting structure affording a greater measure of positiveness and safety in the resetting, safe lighting and 100% control functions.

A further object of the invention is to provide an automatic safety valve construction of the character described incorporating an improved supporting and actuating means for the valves whereby the latter are at all times positively held in alignment with their respective valve seats and in which the valve supports afford sufficient orientation of the valves to permit them to be properly self-seating under spring action.

The invention possesses other objects and features of advantage, some of which, with the foregoing, Will be set forth in the following description of the preferred form of the invention which is illustrated in the drawings accompanyin and forming part of the specification. It is to be understood, however, that variations in the showing made by the said drawings and description may be adopted within the scope of the invention as set forth in the claims.

Referring to said drawings:

Figure 1 is a cross-sectional view of a safety valve mechanism constructed in accordance with the present invention.

Figure 2 is a cross-sectional view of the valve mechanism taken substantially on the plane of line 2-2 of Figure 1.

Figure 3 is a side elevation of the valve shown partially in cross section illustrating the parts shown in Figure 1 in a different position,

Figure 4 is a cross-sectional view showing a modified form of the valve mechanism.

Figure 5 is a cross-sectional view of the valve mechanism illustrated in Figure 4 and is taken substantially on the plane of line 55 of Figure 4.

The safety valve mechanism illustrated in the accompanying drawings includes a valve body 5 formed with an internal passage I for gas or other fuel and which is connected at its opposite ends to inlet and discharge openings 8 and 9 which are preferably appropriately threaded for connection thereto of conduits II and I2. Formed interiorly within the passage 1 are a pair of annular valve seats I3 and I4 and which provide together with the passage 1 adjacent chambers for valves I6 and H. Preferably and as here shown the valve seats I3 and M are provided on the opposite ends of a tubular insert member I8 which may be threaded into the bore defining the interior passage 1 so as to thereby locate the valve seats I3 and I4 concentrically within the passage and coaxially aligned with relation to each other. Insertion of the member I8, as well as other parts to be hereinafter described into the body is here afforded through a side opening l9 formed in the body in alignment with the location of the member l8, and which is normally sealed off by a closure plug 2|.-

Valve mounting and motivating means is provided within the interior passage 1 for guiding and actuating the valves l6 and I1, to and from their respective seats l3 and I4 so as to thereby selectively close and open the passageway 1 between the inlet and discharge ends of the passage. This means is composed of a longitudinal assembly extending axially through the valve seats l3 and I4 and centrally supporting the valves l6 and l I in alignment with the seats. More specifically the assembl consists of a pair of telescopically arranged slidably connected sleeve and rod sections 22 and 23 and a stem extension 24 projecting from one end of and fixed to the sleeve section 22, the stem 24 and the distal rod end 26 at the opposite ends of the assembly being slidably mounted through openings 25 and 28 formed in the plug 2| and an opposite endwall 29 of the body, and which openings 25 and 28 are axially aligned with the valve seats I3 and I4. Reviewing the above structure, it will be noted that stem 24 is fixed to sleeve 22, rod 23 slides in sleeve 22, and the distal rod end 26 is formed as an extension of and is fixed to rod 23. Preferably a sealing gasket 21 is mounted in opening 25 so as to seal the rod therein. The valve I6 is here formed of a metal body 3| having a cylindrical portion 32 surrounding the sleeve section 22 and an end-flange 33 facing the seat l3. The metal body 3| is preferably covered in its entirety with a suitable valve seating material such as rubber, neoprene or the like and which is formed at the end of the cylindrical portion 32 away from the flange 33 with an enlarged ring 36 which slidably engages the sleeve section 22 in sealed engagement and affords a limited swivel or universal movement to the opposite sealing face of the valve which engages the seat I3. The valve I6 is normally urged to its seat I3 by means of a frustro-conidal helical spring 31 which is supported at its base in the closure plug 2| and is compressed against the backing flange 33 of the valve.

Valve I"! is preferably constructed similarly to valve |6 with a metal backing member 38 covered by a valve facing material 39 and which also provides an O-ring type of sliding and sealed engagement 4| with the rod section 23 thereby affording a limited swivel or universal movement to the seating face of the valve on the seat l4. Helical sprin 42 compressed between the endwall 29 of the body and the re-enforcing flange of member 38 of the valve, normally urges the valve I! to its seated closed position on valve seat |4.

The interior end 43 of the sleeve section 22 is normally positioned as shown in Figure 1 in abutment with the valve l1 and the sleeve section is normally urged interiorly into the body by means of a frustro-conical helical spring 44 supported at its base by the closure plug 2| and compressed at its apex against the adjacent end 46 of the sleeve section. In accordance with the present construction the spring 44 has a somewhat greater compressive force than the sprin 42 so that the sleeve section 43 is normally displaced to the right as viewed in Figure 1 against the valve l1 and its closing spring 42 so as to thereby normally maintain the valve I! in open position. Thus in the position of the parts illustrated in Figure l and which corresponds with the shut off position of the device, valve I6 is moved by its spring 31 to closed position while valve 38 is moved by spring 44 to an open position, the latter being resisted by spring 42.

In runnin or "on position, valve I6 is held in open position against the action of spring 31 by means of a temperature responsive latch here denoted generally by numeral 41. This latch functions by holding the distal end 26 of the rod section inwardly displaced with respect to the mechanism above described so as to effect a holding open of valve |6 by means of a cross pin 48 carried by the rod section 23 and projecting radially through slots 49 provided in the sleeve movement to closed position under the action of spring 31 to thereby shut off the flow of fuel through the device which is connected in the fuel line to the main burner, the main burner being connected to the discharge conduit |2. Different types of thermally responsive latch means may be used for the purposes described. For example a bimetal latch of the type disclosed in Jenkins Patent 2,322,520 issued June 22, 1943 may be used. In the present disclosure, however, a different type of thermal latch is preferred and is illustrated consisting of a tube 52 connected to and extending from the body 6 perpendicular to the wall 29 and parallel to rod section 23. Secured to the outer end 53 of the tube and supported thereby centrally within the tube is a rod 54 having an opposite free end 56 arranged in juxtaposition to the rod section end 26. The tube 52 is preferably constructed of a material having a relatively high coefiicient of thermal expansion and relatively low coefficient of thermal conduction, such as stainless steel, and the tube 52 is so positioned with respect to the pilot burner 5| that one side only of the tube is heated by the pilot flame. Accordingly the reater expansion of metal on the heated side of the tube 52 causes a slight deflection of the tube when heated, as contrasted to its cool condition and this small deflection of the tube is amplified greatly at the free end 56 of the rod 54 so as to swing the free end 56 into and from alignment with the rod end 26 upon heating and cooling respectively of the tube. The opposed ends 26 and 56 of the rods are preferably formed as hardened steel pins so as to maintain proper abutting surfaces over small areas of contact. The pin 56 is desirably positioned eccentrically to the rod 54 and the tube 52 is eccentric to the pin 26, as will be seen in Figures 1 and 2, which affords adjustment of the amount of overlap between pins 26 and 56 on rotation of the tube 52 relative to the body 6. Preferably the tube 52 is threaded into the body 6 as herein shown so as to facilitate such rotational adjustment and is held in adjusted position by a lock nut 51.

The pilot burner 5| is of more or less conventional design including a pilot tube 58 mounted on an orifice fitting 59 threaded into the body 6 in registration with a pilot gas passage 6! provided in the body and extending to a threaded socket 62 provided in the body for a pilot gas conduit 63, see Figure 2. The pilot tube 58 extends from the body in parallel relation to the tube 52 and generally under or below th tube and is provided on its top side with a plurality of gas ports 64 which support a series of small flames serving to heat the adjacent side of the tube 62 when the pilot burner is in operation. Upon extinguishing of the pilot burner the heated and unheated sides of the tube rapidly reach the same temperature with a corresponding deflection of the rod end 56 so as to release the abutted end 26 for closing of valve l6 as above described.

In order to position the rod ends 26 and 56 in end-wise abutment from the overlapping position of these parts as illustrated in Figure 1, manual displacing or resetting means is provided at the opposite side of the body. This means here consists of the extension of the actuating stem 24 above described, through opening 25 in the closure plug 2| and the provision of a knob 66 on the outer end of this stem. The stem 24 is integrally secured to the sleeve section 22 as by'means of a, pressed fit or the like so that on manual withdrawal of the knob away from the body, the sleeve section 22 is likewise drawn in the same direction. This movement of the sleeve section 22, to the left as viewed in Figure 1, withdraws the sleeve section end 43 from the valve 38 thereby permitting this valve to move to its seated position under the urge of its spring 42. Continued movement of the sleeve section brings the end 61 of slot 49 against pin 48 so as to thereby draw the rod section 23 and the pin 48 with the sleeve section. This movement of the pins 48 causes an opening of valve is against the action of its spring 31 and a movement of rod section end 26 into endwise abutment with rod end 56 of the thermal latch. Starting from a position of the parts as illustrated in Figure 1, ignition of the pilot burner and corresponding deflection of the thermal tube 52 will cause the latch end 56 to bear forcibly against the rod end 28. Thus as the rod end 26 is moved in the resetting operation to a point clearing the free end of pin 56, the latter swings to overlapping relation with the rod end 26 thereby holding the rod assembly against return movement. This position of the parts is illustrated in Figure 3 of the drawing, wherein it will be seen that the abutting ends 26 and 56 hold therod section 23 displaced to the left as illustratedin Figure 3 and thereby hold the valve H5 in open position. In this resetting operation, that is the pulling out of the actuating stem 24 by means of knob 66 so as to change the position of the several parts from that shown in Figure 1 to that shown in Figure 3, it is important that valve 38 be seated before valve [6 is opened. Valve 16 as above noted provides the main shut off valve for the device and the opening of this valve normally permits the flow of fuel to the main burner. It is highly desirable that the flow of fuel to the main burner be shut off during the period of setting of heating appliances into operation that is during the period of lighting the pilot burner and setting the safety mechanism. Such a construction is normally referred to in the art as safe lighting. This safe lighting construction is here afforded in the lost motion connection provided between the sleeve and rod sections 22 and 23 as defined by the cross pin 48 and the longitudinal slots 49. As will be seen from Figures 1 and 3 the length of the slots 49 and more particularly the distance between the slot end 61 and pin 48 is somewhat greater than the distance between the valve I! and its seat 14. Thus on pulling out of the knob 66 in the resetting operation the sleeve section 22 travels the distance between the slot end 61 and the pin 48 before the pin 48 is picked up in the movement to thereby open valve l6. In this manner in the resetting operation, valve 11 is first closed to thereby prevent the flow of fuel to the main burner before the safety valve 33 is opened to thereby admit fuel from the intake passage.

After the device has been reset, as depicted by the positioning of the parts in Figure 3, the knob 86 may be released so as to permit its return under the action of spring 44. This return movement of the sleeve section 22 again causes the inner end 43 thereof to bear against the valve I! so as to displace this valve to its open position as shown in Figure 1. Thus in the on or running position of the device, the valve I1 is held in open position by the superior compression force of spring 44 and valve I6 is held in open position against its closing spring 31 due to the cocked or abutted position of rods 23 and 56.

A modified form of the invention is illustrated in Figures 4 and 5 wherein the fuel supply to the pilot burner is shut off together with the shuttin off of the fuel supply to the main burner upon failure or extinction of the pilot flame. This type of construction is commonly referred to in the art as 100% control and is here accomplished by the taking of the gas or fuel for the pilot burner from the main f-uel passage 1' of the device through a pilot port 68 formed in the valve seat insert member l8 between the valve seats l3 and I4. Fuel so supplied to the pilot port 68 is conducted through a pilot passage 6| in the body 6' similar to that provided in the first described embodiment for subsequent passage to the pilot burner 5|. Regulation of the now of pilot gas or other fuel in the passage 6| is afforded by a needle valve 69 provided in the passage 6|, see Figure 5. Preferably this needle valve is accessible exteriorly of the body 6' for adjustment as indicated in Figure 5. The intake passage 8' of the body appears at the bottom rather than at the top of the figure as differentiated from the device shown in Figure 1, due to the fact that this modified type of safety device is arranged for positioning in the full line ahead of the conventional thermostat control so as to take the pilot fuel from the line ahead of such control, but the flow circuit is similar to the device first described in that the entering fuel from conduit- I I first passes valve l6 and then valve l1 and then to the discharge conduit I2. Thus when the valve I 6' is in closed position the fuel flow to both the pilot passage 68 as well as the discharge conduit II is shut off. In the resetting operation valve I1 is first closed as in the first embodiment so as to prevent flow of fuel to the main burner and thereafter valve I6 is opened which permits flow of fuel to the pilot port 68, the operation of the valves and associated parts being the same as that described in connection with the first embodiment.

I claim:

1. A temperature responsive safety valve comprising, a valve body formed with an interior gas passage communicating at its opposite ends with inlet and discharge openings and formed inte riorly with a pair of annular valve seats and valve chambers adjacent said seats, first and second valves mounted in said chambers respec tively and movable between open position spaced from said seats and closed position engaging said seats, valve supporting and actuating means carried by said body comprising slidably engaged first and second parts and supporting said valves for their movement aforesaid, first and second springs connected to said first and second valves respectively and normally urging them to closed position, a third spring connected to said first part of said actuating means for urging said second valve and normally functioning to displace said second valve to open position against the resistance of its spring, said first part exten ing from said body for manual engagement and displacement against the resistance of said third spring and said first spring and on such manual displacement permitting the closing of said. second valve and causing the opening of said first valve, the sliding construction of said parts producing in said last named displac ment a c osing of said second valve prior to the opening of said first valve, and a temperature respons ve catch engageable with said second part of said actuati means upon manual displacement as afores id and in caught position functionin to ho d said first valve in open position, said slid n construction of said parts permitting a r turn of said first part upon manual release under the action of said third spring and a corres onding openina of said second valve'against the action of its closing spring.

2. In a main and pilot burner system a temperature responsive safety valve comprising, a valve body formed with an interior gas passage communicating at its opposite ends with inlet and discharge openings and formed interioriy with a pair of annular valve seats and valve chambers adjacent said seats, first and second valves mounted in said chambers respectively and movable between open position spaced from said seats and closed position engaging said seats, valve supporting and actuating means carried by said body and composed of first and second slidably attached sections having a lost motion connection therebetween, each of said sections being formed with an abutment means, said first valve being slidably carried in sealed engagement on said first section and engageable with said abutment means on said second section, said second valve being slidably carried in sealed engagement on said second section and engageable with said abutment means on said first section, first and second springs engaging said valves respectively and normally urging them to closed position, a third spring connected to said first section and normally displacing said second valve to an open position against the action of its closing spring, said first section extending from said body for manual engagement and displacement against the action of said first and third springs thereby permitting the closure of said second valve and causing the opening of said first valve, said lost motion connection being such as to produce on said last named displacement a closing of said second valve prior to the opening of said first valve, and a temperature responsive catch engageable with said second section upon manual displacement ofsaid first section as aforesaid and in caught position functioning to hold said first valve in open position, said lost motion connection being constructed to permit a return of said first section upon manual release under the action of said third spring and a corresponding opening of said second valve against the action of its closing spring.

3. A temperature responsive safety valve comprising, a valve body formed with an interior gas passage communicating at its opposite ends with inlet and discharge openings and formed interiorly with a pair of coaxial valve seats and valve chambers adjacent said seats, first and second valves mounted in said chambers respectively and movable between open position spaced from said seats and closed position engaging said seats, valve supporting and actuating means carried by said body and composed of telescopic slidably attached sleeve and rod sections extending centrally through said aligned valve seats, said first valve being slidably secured in sealed relation to said sleeve section, said second valve being slidably secured in sealed engagement to said rod section, an end face of said sleeve section being positioned for engagement and displacement of said second valve, said sleeve section having a longitudinal slot intermediate said valves, a pin secured to said rod section and extending radially through said slot for engagement with and displacement of said first valve, said pin being engageable with the ends of said slot to provide a joint movement of said sleeve and rod sections and said slot being of predetermined length to afford a predetermined length of lost motion connection between said sections, first and second springs carried by said body and engageable with said first and second valves respectively and normally urging said valves to closed position, a third spring carried by said body and engageable with said sleeve section and displacing the latter against said second valve to move the latter to open position against the action of said second spring, a manually engageable part connected to said sleeve section and extending from the body for displacement of said sleeve section against the action of said first and third springs thereby permitting the closing of said second valve and causing the displacement of said pin through said lost motion connection to open said first valve, the aforesaid predetermined length of said slot being such as to permit theclosing of said second valve prior to the opening of said first valve upon the described manual displacement of said sleeve section, and a temperature responsive catch engageable with said rod section upon the described manual displacement as aforesaid and in caught position functioning to hold said first valve in open position against the action of said first spring, the aforesaid lost motion connection being constructed to permit the return movement of said sleeve section upon manual release thereof to thereby displace said second valve to open posiill tion, said rod upon release from its said caught position permitting the closing of said first valve by said first spring.

4. A temperature responsive safety valve comprising, a valve body formed with an interior gas passage communicating at its opposite ends with inlet and discharge openings and formed interiorly with a pair of annular valve seats and valve chambers adjacent said seats, first and second valves mounted in said chambers respectively and movabl between open position spaced from said seats and closed position engaging said seats, valve supporting and actuating means carried by said body and composed of first and second slidably attached sections having a lost motion connection therebetween, said first valve being slidably carried in sealed engagement on said first section and engageable with abutment means on said second section, said second valve being slidably carried in sealed engagement on said second section and engageable with abutment means on said first section, first and second springs engaging said valves and normally urging them to closed position, a third spring connected to said first section and normally, displacing said second valve toan open position against the action of its closing spring, said first section extending from said body for manual engagement and displacement against the action of said first and third springs thereby permitting the closure of said second valve and causing the opening of said first valve, said lost motion connection being such as to produce on said last named displacement a closing of said second valve prior to the opening of said first valve, and a temperature responsive means having a part movable into end-wise alignment with said second section when said temperature responsive means is heated to thereby hold said second section in its displaced position upon the described manual displacement of said first section, said lost motion connection being constructed to permit a return of said first section upon manual release under the action of said third spring and a corresponding opening of said second valve against the action of its closing spring, said temperature responsive means being constructed to displace said part thereof out of alignment with said second section upon cooling of said means to thereby release said second section and said first valve for movement of said first valve to closed position under the action of said first spring.

5. A temperature responsive safety valve as characterized in claim 2 wherein the temperature responsive means is composed of a tube extending from said body in substantial alignment with said second section, a rod secured to the distal end of said tube and extending longitudinally substantially axially thereof for movement into and from end-wise abutment with said second section, and a ilot burner mounted so that heat generated therefrom will impinge on one side only of said tube, said tube functioning when so heated to position said rod for end-wise abutment with said second section and functioning on cooling to displace said rod away from said end-wise abutment.

6. In a main and pilot burner system a temperature responsive safety valve comprising, a valve body formed with an interior gas passage communicating at its opposite ends with inlet and discharge openings and formed interiorly with a pair of annular valve seats and valve chambers adjacent said seats, first and second valves mounted in said chambers respectively and movable between open position spaced from said seats and closed position engaging said seats, valve supporting and actuating means carried by said body and composed of first and second slidably attached sections having a lost motion connection therebetween, said first valve being slidably carried in sealed engagement on said first section and engageable with abutment means on said second section, said second valve being slidably carried in sealed engagement on said second section and engageable with abutment means on said first section, first and second springs engaging said first and second valves respectively and normally urging them to closed position, a third spring connected to said first section and normally displacing said second valve to an open position against the action of its closing spring, said first section extending from said body for manual engagement and displacement against the action of said first and third springs thereby permitting the closure of said second valve and causing the opening of said first valve, said lost motion connection being such as to produce on said last named displacement a closing of said second valve prior to the opening of said first valve, a thermally expansible tube secured to and extending from said body in substantial axial alignment with said second section, a rod secured to the distal end of said tube and extending substantially centrally thereof to position the inner end of said rod in opposed position to the end of said second section, a pilot burner extending from said body in generally parallel relation to said tube and heating one side only of said tube, said body being formed with a gas passage for said pilot burner which is connected to said interior gas passage between said seats, said tube when so heated flexing to position said inner rod either in end-wise abutment with said second section when the latter is manually displaced as aforesaid so as to thereby hold said first valve in open position, said lost motion connection being constructed to permit a return of said first section upon manual release under the action of said third spring and a corresponding opening of said second valve against the action of its closing spring, said tube flexing upon extinguishing of said pilot burner and cooling of said heated side of said tube to displace said inner rod and away from end-wise abutment with said second section to thereby release said second section and said first valve for closing of said first valve under the action of said first spring.

DONALD F. DROW.

No references cited. 

